Lawn Tractor Quits After 15 minutes Full Explanation 

Husband and I are so grateful for your play by play of this video. We cannot spend more money on our problematic mower. We could spend more money for a new one. We stumbled upon your video. Husband is mowing now. Hopefully, the mower is fixed. Thank you so much again. Humbled family.

Just to share an experience that may be helpful to others... I have a commercial w/b mower. It is old, but I run it every day, a few hours every day. I have worn out two Kohler Command Pro 15 engines. The only replacement I could find that fits the space envelope, a single-cylinder B & S Intek, 500 cc, 17.5hp. I now have about 600-700 hours on it (no meter). The engine has run pretty well. A few days ago, it started a pattern: 20 minutes of running, then sputters and dies (just as if it ran out of fuel). I can restart, and it will run for 8-10 minutes, sputters, dies. I can repeat the cycle, and next time, 3-4 minutes. Another cycle may get the run time down to 1 minute. My suspicion was ignition module - gets hot and fails. However, the pattern was "running out of fuel." I changed out fuel filter. Same thing. I changed out ignition module. Same thing. I changed out spark plug (maybe cracked and heat took a toll). Same thing. I took off fuel line to carb, blew some light air into carb. I took out the carb jet and cleaned. Same thing. I cleaned out tank cap, and made a new gasket. Same thing. Then I started tracing back fuel line. When I took off fuel line to carb the first time, it had been sitting for an hour or more. I did get fuel draining out, so concluded fuel supply was good. However, in a desperate move, I took off the line to the carb again. This time, it was sitting only a minute. I got hardly any flow. Now, I am convinced the problem was fuel supply (which I suspected at the get-go). From the carb - took out the filter. No change in flow. Then I took off to the vacuum pump. No change in flow. I took the line off at the shut off valve (which you don't have). No change in flow. The next step back is to the orifice at the bottom of the fuel tank (it sits about three inches above the carb - I my not need the pump). I put my air blow into the line, and then got blowout through the top of the tank. And, I got full fuel flow out of the tank!!! The problem was traced back to something blocking the outlet orifice of the fuel tank. I took off the tank, flushed it out, and reinstalled. I've ran it now for a couple of days and it works fine. The blockage must have been partial. When sitting for a long time, enough fuel seeped through the orifice into the lines, the pump and filter, to allow the engine to run for 20 minutes. When I restarted again, less fuel was in the line, filter, pump, hence shorter run time. With each successive start, the time was less because less fuel passed through the partially blocked orifice. In hindsight, it all makes sense! Sorry for the detail. But, I wanted to explain my diagnostic path. The problem was inside the fuel tank. Maybe this will be helpful to somebody with the same shut-down pattern. The machine is 24 years old, the tank has never been off. In early years I ran it about 600-700 hours per season (uses about 0.6 gal/hr - means ~400 gallons of fuel per season). Now, I only run it about 400 hrs (bought a rider to use in parallel). Of all the years of running this machine, and others, I've never had one with a partially blocked orifice at the bottom of the tank.

I was having the same "tractor quits after 15-30 minutes problem". Watched your video. I had previously replaced my fuel filter with the same oversized one that you did. I tried to be careful to minimize air left in the fuel filter to assure fuel and not air is on the vacuum side- it only had a tiny amount of air left in the filter when I had replaced it. So I checked the tractor over when it was cutting out- the fuel filter no longer had enough fuel in it and the vacuum was sucking air even those the filter was half full with fuel. I slightly tilted the fuel filter to assure if any fuel was left in filter that it would be sucked in by vacuum and NO MORE PROBLEM! Thanks for your video!

Thanks for the video. My gas cap hole was plugged and you fixed it for me.

Thanks you are the greatest my John deer would quit after 15 minutes followed your advice with clearing the gas lines

Congratulations on resolving your tractor problem. As you cursorily mention, there are numerous elements which can cause engine stall after 15 mins. Changing parts willy nilly may not always prove to be a good substitute for problem determination. For instance, it is possible for a new coil (and other new components) to be defective so it is better to determine the actual failed component.

Thanks. Seeing the new filter filling up so fast let me know I’ve got more searching to do. My new filter will fill, but by gravity if I let the mower sit. Starts and runs fine a couple minutes, then surges. The fuel filter isn’t filling. Gets sucked dry, then surges. Going to check my gas cap and the fuel pump vacuum line next.

I fixed it....reversed air pressure fuel line to tank was plugged.....runs at full power for as long as I want now Thank you...great vid

I use a pair of vice grips on my gas line when I unhook it then run the line into a soda bottle to check the flow. No gas spillage.

Really helped me out. Thank you for the clarity and step by step fault finding without needing a full strip-down. MIne a Countax with a Briggs and Stratton 13.5 HP engine. Fuel filter AND oil...Cheers

Note: On some of the newer mowers there is an oil sensor that will shut the engine off if the oil gets too low. Cool vid.

Neato! Thanks. I appreciate how you run through the various issues that you may have in one video.very concise.

My mower would run great and then conk out after 20 minutes, like clockwork. After sitting for a couple of hours, it would start, run great and stop after 20 minutes. I figured it wasn't something random like dirt floating around the system. That wouldn't make sense. I went through all the easy routine fixes anyway, same thing over and over. Then, just as I was about to give up, I noticed some bits of grass hanging down from the cooling fin cover. I gave it a few tugs and got nothing, it was obvious something was stuck up there. I took the cover off and found mouse motel baked on, grass, acorns, the whole shebang! It must have gotten to the overheat stage at 20 minutes and shut down until it cooled off enough to continue. It was an interesting learning experience. If I ever have that problem again, I'll know where to look first!

My Snapper LT145H38DBV is over 20 years old, was purchased new, and has hydrostatic drive, which means it runs full tilt most of the time. It has never been to a shop for maintenance, but my son did keep it at his house for a few years, which may explain some of the problems I've had. Within the past year or two I've replaced the ignition coil, the battery, the starter, the solenoid, added a fuel cut-off valve, added a fuel filter to the gas line, cleaned the jets in the carburetor and other things in order to address various issues as they arose. Where I live, in the Southeastern part of the USA, the temperature in mid-summer after 10:00 am is routinely above 95 degrees F, with a heat index of about 105 to 110. The problem I'm having seems to be vapor lock. I drilled a bigger hole in the gas cap to eliminate any vacuum issues, and the bottom of the gas tank is above the carburetor, so no fuel pump is involved. As with yours, after cutting full bore for 15 to 20 minutes it cuts off, and there is no fuel visible in the clear fuel filter housing. Filling the tank up cools the hot fuel down and after a few minutes I can get it going again. There is a possibility of trash in the outlet of the molded plastic gas tank, or I need to insulate the fuel line with a shield of some sort to keep engine heat away from it. Thanks for all of your tips in tracking down this type of problem. If it gets worse, and my approach doesn't work, I found and bought an OEM replacement carburetor on eBay, and have it ready to install when necessary.

Good job, I had a similar JD mower, it’s problem was the fuel flow related, I replaced the fuel pump, but it still would not run, the real problem was the soft vacuum hose that ran from the fuel pump to the carb intake manifold, The fuel pump gets its vacuum to activate the fuel pump from the intake manifold, the vacuum hose had a split on the motor side so I could not see it, I finally had tried everything I knew to do, so just bought a new vacuum hose, when I took it off I squeezed the hose, that is when I saw the split it the hose, What a pain it the back side that problem was to find, New hose new fuel pump, it ran like a top,

Thanks for pronouncing solenoid correctly.

Thanks for sharing this video with us.

I listing to this music while I get my mow on with my mtd yard bug I painted purple and named Pamela Morrison..she's a fine machine..

Thanks for the vid. Hadn't thought about the fuel cap.

Excellent video on fuel system blockage repair very helpful.

THX... YOU KNOW WHAT I WILL BE DOING TOMORROW MORNING.....

Always the simple fix. Great vid. Most of these yt wizards would have had you tearing the carb down.

Fuel line clamps are very cheap and prevent gas spillage :)

mine (2020 cub cadet xt1) wanted to quit on me after 10-20 mins of mowing… i changed fuel filter and runs beautifully now!

Don't have air you probably could loosen cap enough to get air vacumn release and if it solves problem clean out vent or get new cap. Yeah I have had the problem of a bad coil causing a motor to stop after engine gets hot. Loosing fire. After sitting a while the coil cools down and makes contacts until it gets hot again/expansion. Not much to change a coil. Just take off engine cover. Unscrew the two little bolts holding coil. Place a business card between the new coil arms and the flywheel and reinstall bolts. Then turn flywheel until card comes out. That makes near perfect gap.

Thank you SO MUCH for this video!

I think this is my older kubota's problem. I'm cleaning everything from tank bottom, to beginning of carb, and replacing fuel hose and filter. Thank you 👍

I had a self propelled mower that started dying after about 5 min of running. I changed everything, lines, fuel filter, took the carb apart cleaned it and installed new gaskets, everything I could think of. Then, after a couple of hours, I was on my knees with my head next to the motor, glasses on, watching the fuel in a clear line I bought at the hardware store. My hand was on the gas cap and I loosened it a little. There was a sucking sound as air went into the tank. I took the cap off and realized the alcohol had swelled the rubber and closed off the vent hole!!?## I used an exacto knife and carefully widened the hole in the rubber. Problem solved. Since then I had it happen on another engine. If you are at your wit's end, loosen the cap first and try it to make sure that's the problem. Just be careful that you don't go too far and make a hole that will cause the cap to leak fuel (or just buy a new one). I've never heard of a similar problem on a riding mower tank, but when I saw this said "15 min", I thought that might be how long a larger tank would take. These mower videos are great you can't watch too many you always learn something new to pass on to the next generation. Good job on the video.

If your mower is doing this and it ends up not being your fuel cap. Check to make sure the screws on your carburetor are not loose. Sometimes they loosen up slightly over time and the carb will start to suck air when hot. If that still doesn't fix it, then clean your carb or buy a new one for $20.

I have a John Deere mower that's two years old. The last time it was serviced was the last of July this year. After mowing for the second time afterward, the mower sounded like it wanted to cut out and it did after I finished mowing. It cut out in my backyard where I store it. Every time I tried to start the mower it wouldn't stay running and HUGE plumes of white smoke billowed out. Not knowing what to do I watched some videos, went to the mower and checked the oil. The reservoir was full of gas. A week later I drained the gas out, poured in two quarts of oil, drained THAT out and poured in two more quarts. I saw this done on a video. I didn't smell any more gas. I still haven't tried to start the mower and mostly because I was waiting for a mower repair guy to come to my house this weekend. After watching your video I am going to change the gas filter like you did but first I will remove the old (and clean) gas filter, use my air compressor and gently blow air through the lines. I have a new oil filter but I don't have an oil wrench. I'm sure the mower repair guy has one. I have a feeling that after my mower was serviced and I filled the gas tank up, some debris may have gotten into the gas line. If this is the case, I hope the gas tank doesn't have to be removed and dumped out.

i had a problem with my harqvarna when it got hot out when cutting the lawn. i fixed the problem . the fuel lines are to close to the motor so i insulated the lines and no more problem.

So. I have experienced the same problem. Runs 20 minutes and then carburetor runs dry. I I’ve had this problem since I bought new. I disconnect at fuel pump, prime tube with gas, and then it starts and runs. But what I think the problem is there is no venting. I do not have a vent hole on the gas cap, and not sure where the vent hole is. So what I do now is loosen the gas gas every so often while I’m cutting. Since doing this the mower has not stopped running. It only took 10 years to figure this out. Hope this helps.

Thank you. Finally someone not just saying it's the fuel cap

Having the same problem. Have the same B&S Intek 22hp. After checking several things I had both coils tested and the machine said they were bad. Replaced them still same problem. Now I'm going to check the valve clearances. This is driving me nuts!

Some fuel filters are designed for engines with a fuel pump and other fuel filters are designed for engines without a fuel pump. Get the right filter. I was sold a filter for an engine WITH a fuel pump and my mower has no fuel pump. It shut off after 15 minutes due to lack of fuel. Fuel did not free flow well out of the filter. It free flowed very well out of the line to the filter. I put the right filter on and no more problem.

i came here to see if you were going to show how to fix the gas cap. i had the same problem. bought a oem gas filter and oil filter . changed out the gas one. same problem . went to u tube , and found out i should loosen the gas cap. if I don't have a problem, its the gas cap. john deere ran like a champ. so i need a gas cap or to repair it. ( the parts i bought , cost less then $20). i need to change the oil soon anyways. so every , try to loose your gas cap. if it doesn't breath it creates a vacuum and no gas will flow.

Good info, thanks

Great info, thanks

It’s funny watching this video,…I had been thinking that my gas cap vent is plugged on my side by side.

Eliminate the background music so We can hear

good info video! I'm becoming a Ms Fix-it, LOL.

I have the Briggs and Stratton 17.0 engine. I am looking at all the things you’re pointing out and my fuel filter isn’t what I’m normally seeing. The fuel filter is about as round as a quarter and about 3/4 of an inch thick. Hmm 🤔 I’ve always seen them like what yours has. Should I change this tiny little thing out for the bigger one?

You the man keep doing

Glad it was the fuel filter but also you did cover the thing,s to be looked at as the possible cause of the engine shutting down

My mower is doing the exact same thing now, runs 15 minutes and quits. I’ve done the basis as I’ve had the mower for 2 yrs without doing anything. Didn’t think of the gas cap. I’ll do that next then it’s on to the spark plug coils.

Ignition Coil... (and while you have the fuel filter off... CHANGE IT...!) No the fuel pump ACTUALLY DOESN'T work on vacuum, it pulses on POSITIVE CRANKCASE PRESSURE from movement of the piston...

I bought gas tank cap for $45 plus tax and it was not exactly the same but a compatible to one I am replacing, I also replaced fuel filter, but still after 15 20 minutes tractor dies (quits) what could be other possible issue I should look for? Thanks

Thanks, super helpful.

Ok, my motor is running hotter than it should. It is very dirty and I'm wondering if I can hose it off? Is there an area that I should be careful about water hitting it.

I cleaned the carburetor which was super clean (my lawnmower is almost a year old) and replaced the fuel filter and once I engage the blades it'll run anywhere from 5-20 minutes and starts to shut down but if I turn the choke on it'll run fine. Any suggestions?

Great vid, another issue that may cause this issue is a faulty fuel solenoid .

He made it look easy. Can he come to my house after I get the part?😁

Quick comment: great video and helpful, however, with the background music I could not hear important stuff like the air pressure doing it's thing.

what happens if I accidentally put 95 octane gasoline to my lawn motor.. could it cause the hot increase issue? I forgot to buy the 91 octane gas.

KOHLER recommends a gravity feed fuel system use a 75-micron fuel filter or larger.

Turn the music off. Great help…thank you!!

I just learned that the cap part always is closest to the carb

The safety seat module can be loose or bad too.

We instantly diagnosed the problem, it’s a Briggs & Stratton!!!

More of a key point is there's a lot of Fail-Safe switches any of which will prevent starting

I dont have an air compressor though

Sounds like it could be a vacuum leak. The mower will run until the gas supply runs too lean and then turn off. If when it turns off the fuel filter is empty or near empty. A vacuum leak is most likely the cause. Changing the filter helps extend the time until it turns off because it is easier for the fuel pump which runs off vacuum to pull through a clean filter....

had a problem with Kubota z121 stalling when making turns. Found the fuel tube inside tank was sucking directly on bottom of fuel tank. This was stopping fuel flow. Pulled hard tubing out of top of tank cut it about a 1/2" at a 45 degree angle and reinstalled. No more problems. Would not have thought this would be an issue but didn't have a problem until it was over 2 years old. I thought it was water in tank, trash in tank, carburetor, fuel filter. fuel lines traced it back into the tank. So always start at the tank first, try looking at hose inside the fuel tank at the bottom if possible. Could have been trash in tank getting stuck in line and then unstuck once fuel pump stopped. Like a piece of grass or wood to big to go into the hose but small enough to let some fuel get into the hose. So always check tank really good. Hope this helps someone before going through all the other checks first.

i see u had the hose off the carb and u put it in a tub and the motor ran for a good while how can that happen with no fuel to the carb

K&D_Enterprise9 have you heard of this problem? My 16 yr-old riding mower - Kawasaki engine- starts right up when cold. If I pull it out of the garage and shut it off to fuel up, it will not restart for at least 15-20 min. If I take a break from mowing, when I go back to resume mowing, it will not restart for another 15-20 minutes, but it will eventually start. My mechanic is baffled because, of course, it won’t fail for him . Any ideas? Thanks!

That old 80s porn music really brings me back. So your test was almost an hour, and you were pulling an aerator. I'm curious if you were using your mower deck at the same time? Were you having stalling problems when using your mower deck? I ask because I was pushing my dethatcher, mower deck turned off, and it worked fine, for hours. But when I decided to turn my deck on, it was only while under load that it would stall out after 15-30 minutes or so. Then I would hit the PTO off as fast as I could and it would continue running. I continued this process for a while to test my theory, and sure enough, it would only begin to stall out while under load. If I didn't happen to be dethatching, I never would have know that. Mine is still a work in progress.

I just noticed my lawnmower when I usually put gas in it I can't fill it up because it runs out but now I put gas in it filled up and ran out slow

my Husqvarna walk behind four-wheel-drive mower starts quitting intermittently after about 10 minutes. It is not the gas cap vent., it’s not a dirty carburetor, it is not low on oil,.. I am suspecting the emergency shut off system. I have not investigated deep into that possibility yet. We have two mowers, when this one keeps quitting I just get the other one which is a 2 Wheel Dr., Husqvarna walk behind… I took the carburetor off and cleaned it, I added an in-line, see-through fuel filter, the air cleaner is cleaned, it starts right up. Is it possible that it could be a low oil level built-in safety like my generator has? My small 1400 W generator will shut off if the generator is low on oil, or if it is not reasonably level… One additional check, it is not out of gas, or even near out of gas when it starts shutting off. Our property has Rollinghills, but it is not always on a hill when it starts shutting off… I checked the coil connections, I checked the gap at the flywheel, I did a resistance and continuity check on the coil.. this Husqvarna, A221 is about six years old. When it shuts off, it says though the ignition quits. It does not suddenly stop instantly. It whines down slowly when it quits over about three seconds, so it is not seizing… compression feels good/high. It is not leaking oil, does not have a bent crankshaft. It has the original drive belt for the four wheels… The engine was made by Briggs and Stratton.. The engine has never been apart other than to replace the entire. I’ll start mechanism as one unit with the spring included… that entire assembly for the pull rope I bought on eBay for $17 free shipping, it went right on. The original one lost one of those pop out tabs that engage that starting hub… perfect fit.. The issue acts electrical, i’m suspecting possibly the needle and seat in the float bowl.. I can buy a complete new carburetor on eBay for $11.. That’s my next move

I recently came across the gas cap issue

BUYER BEWARE: I had the exact same problem mowing with an identical machine yesterday. After 10 to 15 minutes the engine would start running rough and cutting out like it wasn't getting any gas and then it would just stop working. I had to let it sit for 10 minutes to a half hour to cool down and then it would start right up and be good for another 10 to 15 minutes. As a result it took me 3 hours to do a 45 minute job. Extremely frustrating. The oil level also seems to overfill itself. Perhaps gas is leaking back into the oil reservoir somehow. It sounds like some kind of a design defects in the machine.

Yeah my fuel cap was blocked..thanks mate.

The problem I have found is the position, mainly the height of the fuel pump along with the vibration of the engine causes vapor lock. Lower the pump below the carb, insulate the fuel lines around the engine and isolate the pump from vibration. It is really just a poor design, any time the fuel is pumped up higher than the lowest point of the carb you have a spot for vapors to collect.

Is this a video on how loud you can play music, while trying to fix a mower. 😂😂. Next up, a video how to dive into a pool while while your filling it up.

Enjoyed the background music...

Thanks. I know I'll never buy that to noisy brand.

No flames ...?

Rubber in fuel tank is sign of bad fuel cap, replace it ASAP

Mine quits after about 15 minutes and it drains the battery

What if the gas cap doesn't have a vent?

Your clamps not on all the way on your fule filter

I changed everything that you show me and still doing the same thing shut off after 15 minutes

Replace fuel cap every 2/3 years and you’ll money ahead Use real gas to

rule number 1 get a turn off value for your gas line

Hmm. Pull that grill a little closer, i feel lije cookin some dogs while i have raw fuel poyrin out, umm hmm. Yep.

Dipstick is stuck, can’t open it

Worked great until my motot locked up

Trashinta NJ

Dude just get to the problem? You don’t have to explain everything that has nothing to do with the problem!

worst design ever made, i got fed up and put an electronic fuel pump on it and never looked back ;-D fu john deer